In this trial, children age 90 d to 6 yrs who are infected with HIV are randomized to receive ZDV or Stavudine (d4T). The objective is to compare the safety and tolerance based on clinical and laboratory evaluations, of orally administered ZDV or d4T in mildly symptomatic HIV infected children. Secondary objectives compare the clinical responses as defined by disease progression and immunologic response as measured by changes in viral burden, p34 antigen concentrations and CD4 cell counts, between the two treatments. The study changed to open label d4T when protocol 152 results indicated AZT alone was suboptimal. Two subjects are now off the study drug on prescription medication. One patient continues d4T alone and is doing very well.